This invention relates to a valve mechanism for a hydraulic expansible chamber motor, and more particularly to a quick-acting valve mechanism for actuating the distributing valve of such a motor.
The invention involves an improvement upon the quick-acting valve mechanism of the type such as shown in U.S. Pat. No. 2,750,932 for a motor having a cylinder and a piston reciprocating therein, comprising a main D-valve sliding on a valve face for controlling the supply of fluid to and the exhaust of fluid from the opposite ends of the cylinder so as to reciprocate the piston and an auxiliary D-valve sliding on the valve face responsive to the approach of the piston to either end of the cylinder for controlling the operation of the main D-valve. Air is the working fluid in the distributing valve and motor of this type and a problem encountered in the operation of the valve and motor is the generation of noise as compressed air flows through the D-valves into the cylinder and expands upon being exhausted from the cylinder. Another problem is the relatively high initial and operating cost of the required ancilliary equipment such as the air compressor and prime mover.